Many people who are living longer after a sedentary lifestyle are paying the price. The diseases osteoporosis and sarcopenia are on the rise, and their underlying biological similarities and common risk factors are creating a new syndrome: osteosarcopenia.
This syndrome exacerbates each disease’s associations with high risk of frailty, falls, fractures, hospitalisation and mortality; indeed, a study confirmed that osteosarcopenia is linked with poorer physical function than sarcopenia alone.
Early diagnosis and intervention for this “hazardous duet” are imperative, so here’s what to know.
Osteoporosis affects more than 60% of Australians over 50 years. It happens with aging when bone tissue starts deteriorating, resulting in porous bones and increased risk of fracture – even with minor falls. It can be diagnosed with a bone mineral density scan.
Sarcopenia, on the other hand, refers to accelerated loss of skeletal muscle mass and strength with aging. Affecting around one in three older adults, it can be harder to detect – especially if a person is overweight. Handgrip is typically used to measure muscle strength and gait to assess physical performance.
Bones and muscles both release hormones that impact the metabolism and functions of other tissues, and crosstalk with fat cells – together these three groups are the biggest constituent of connective tissue.
When muscle and bone tissues break down, they are typically infiltrated with fat cells which creates toxicity and inflammation and interferes with the crosstalk between them.
The only way to diagnose osteosarcopenia is with combined detection of each disease.
A history of falls and/or fractures should sound warning bells. Shortened stature is also a clue to fractures of the vertebrae due to osteoporosis. Muscle weakness and wasting can point to sarcopenia, and genetics play a role in both conditions.
People with these risk factors should be regularly screened for each disease, and experts agree that all postmenopausal women over 65 should have bone mineral density scans regardless.
Factors that lead to high risk of osteosarcopenia include older age, being female, endocrine disorders, sex steroids, low protein intake, smoking, inadequate dietary calcium intake, low vitamin D levels, and minimal mobility and function.
It is better to treat osteosarcopenia as one condition, using an integrated approach, rather than the two contributing diseases separately.
Inactivity is a primary, modifiable cause of muscle wasting and bone density loss, as the health of both bones and muscles relies on mechanical stimulus. Resistance training – increasing muscle strength – is most important.
Regular weight-bearing and muscle-strengthening exercises that target agility, strength, posture and balance have demonstrated benefits and are recommended at least three times a week for 20 minutes or more.
Protein is vital for bone and muscle and is recommended at more than 0.8 mg/kg body weight per day. Calcium and vitamin D also have dual benefits for bone and muscle; together with protein they can help reduce falls, fractures and disability.
Regular activity and a healthy diet with adequate nutrition are also the most effective ways to prevent age-related deterioration of bone and muscle and retain independence and optimal quality of life.
One of our staff recently spoke with someone whose father is in an aged care facility. They discovered he had a hairline fracture in his hip – about a week after it happened. The nurse accidentally dropped him when she was helping him out of bed, and it wasn’t reported.
Around one in three older adults suffer from falls, and up to 60 percent will suffer an injury. Three times more people tumble in long-term aged care.
Most injuries are superficial cuts, grazes, bruises and sprains. Some are more serious. Falls cause 40 percent of injury-related deaths in older adults. Hip fractures are the most serious and costly fall-related injuries, resulting in 19,000 hospital admissions for older Australians from 2011 to 2012.
More broadly, falls – and fear of falling – can impact independence and quality of life. But it’s not a cross lotto. Older people can reduce their risk of falls with nutrition and exercise.
Assessment tools can predict risk of falls, to help tailor prevention strategies. These tend to assess physical capacity like mobility, balance, strength and gait. But nutrition status is also a key predictor for likelihood of falling and the gravity of injuries.
Malnutrition and low body weight result from depleted protein and energy stores. This carries multiple adverse outcomes including bone loss and fragility, poorer movement coordination, slower reaction time and diminished muscle strength – all of which increase risk of falling.
Low calcium and vitamin D impact bone health and risk of falls. Low vitamin K also increases bone fragility. Poor eyesight can compound propensity to fall, also impacted by nutrition status. Low levels of vitamins A, C and E contribute to weak vision.
Insufficient vitamin B12 and folic acid can reduce nerve function in extremities, and in the brain lead to confusion. Dehydration, a common problem in older adults, can also cause delirium, as well as constipation and low blood pressure; all increasing fall risk.
Providing a healthy, tasty diet high in protein from eggs, dairy, fish, chicken, nuts and legumes and a variety of foods from the core food groups is an important step towards preventing nutrient depletion and associated risk of falling.
Regular physical activity is important to reduce age-related loss in muscle mass and bone density. Recently, the SUNBEAM trial (Strength and Balance Exercise in Aged Care), tested a program of individually tailored physical activity in aged care.
The program reduced falls by 55 percent, larger than any other study to date according to lead investigator Jennie Hewitt, physiotherapist from Feros Care and PhD candidate at the University of Sydney.
Over 200 aged care residents from 16 facilities in New South Wales and Queensland took part – half of them were randomised to do the program and the other half continued normal activities.
Participants in the program engaged in 50 hours of group-based resistance (strength) training and balance activities over 25 weeks, then a six-month maintenance period.
Not only did falls decrease dramatically in the exercise program group, but participants had considerably better balance and mobility. Some found the enhanced independence life-changing, and rejoiced at being able to go out with their families.
It’s not just about falls; healthier lifestyles and greater mobility have positive ripple effects for happy aging.
Like many confusing nutrition messages, some claim too much protein is bad for bone health. What is the scientific consensus, and what does this mean for people with or wanting to avoid osteoporosis? What other nutrients are important? First, let’s look at osteoporosis.
All living tissues, including bones, are constantly getting rid of old cells and generating new cells. With aging, however, the rate at which bones are replaced slows down.
Osteoporosis, meaning porous bones, happens when too much bone is lost and not enough produced, resulting in reduced bone mineral density and a fragile skeleton easily prone to fractures. It is different to osteoarthritis, which results from degenerated cartilage in the joints.
Sarcopenia – age related muscle loss – is closely related to osteoporosis, and they are impacted by similar factors. Bone health is therefore considered not just a skeletal problem, but a musculoskeletal problem.
Osteoporosis is a significant global concern – one in three women and one in five men over 50 may suffer from a fracture caused by osteoporosis. But there are ways to prevent and even treat it, including physical activity, sunshine and good nutrition.
Calcium is commonly known to be important for bones, and most know vitamin D is important too – it helps bones absorb calcium. Perhaps less well known is that magnesium may also prevent bone turnover and improve bone mineral density.
For good bone health, the National Osteoporosis Foundation recommends dairy products, fish (canned fish like sardines with bones for calcium; oily fish like salmon, mackerel, tuna and sardines for Vitamin D), and a variety of fruit and vegetables for their mineral content (calcium, potassium, magnesium), vitamin C and vitamin K.
Protein is not only a key constituent of muscle, it comprises about 50% of bone volume and around 30% of bone mass. It is also associated with increased production of insulin-like growth factor, which helps make bones, and better intestinal calcium absorption.
Some studies suggest eating too much protein increases calcium excretion in the urine, leading to concerns about high protein intake for bone health. This is thought to occur because protein increases the body’s acidity, so calcium – an alkaline mineral – is released to restore balance.
However numerous studies have refuted this; in fact when calcium intake is adequate, higher protein diets are linked with higher bone mass and less fractures. Any loss may also be offset by increased calcium absorption.
Furthermore, low protein intakes (<0.8g/kg per day) reduce calcium absorption which in turn stimulates the release of parathyroid hormone to tell bones to release calcium and restore its balance in the blood.
What are good protein sources for bone health? Some studies have suggested higher meat consumption increases calcium excretion, but others have refuted that. Soy protein could reduce insulin-like growth factor so may not be a good choice.
Fish, chicken and eggs provide protein. Dairy foods are good protein and calcium sources. Legumes are a good source of protein and other nutrients but should be well soaked then cooked in fresh water to reduce phytates (which could interfere with calcium absorption). Similarly, nuts provide protein along with fibre and other nutrients.
To maintain a healthy acid-alkaline balance, other dietary factors also need consideration. In particular, plant foods like fruit and vegetables abound in potassium and other alkaline minerals, so eating more of these would help prevent bones’ need to release calcium.
Nature, in her infinite intelligence, has gifted us millions of different proteins that supply the music and instruments of the body’s orchestra. These proteins are assembled from twenty amino acids joined in fifty to tens of thousands of different combinations.
Proteins carry most of the trillions of body cells’ workload. Proteins provide bodily tissues and organs, from the executive brain and mighty muscle to the modest skin, hair and nails, with structure and regulate their activities—including thousands of chemical reactions, enzyme production, signal transmission, and physical movement.
Amino acids can’t be stored, so need to regularly come from food. If consulting recommended daily allowances (RDAs), or recommended daily intakes (RDIs—Australian version), popular discourse claims we eat too much protein. Nutrition experts who congregated for two Protein Summits in Washington, US, disagree.
The RDA, or RDI, is calculated to estimate how much of a nutrient will fulfil the body’s basic nutritional needs. Recommended protein intakes average 0.8 grams per kilogram of body weight per day in healthy adults, equating to 10% of most people’s daily calories.
The average person consumes 16% of their daily calories as protein. Although this exceeds the RDA, the Protein Summit consensus, published in the American Journal of Clinical Nutrition in 2015, suggests people should eat at least double that, or around 15% to 25% of daily calories from protein depending on age and activity levels for optimal health—particularly preservation of muscle mass, strength and fat-burning capacity.
Every year, a third of Australians over 65 fall at least once—that’s around a million older adults falling over, potentially increasing to 2.7 million by 2050 as the population ages. Not only can falls cause cuts, bruises, broken bones, disability and even death, costs are estimated to blow out to $1.4 billion by 2051.
That muscles need protein is well-known—less well appreciated is that 50% of bone volume and about a third of bone mass is made from protein. Dietary protein is critical for making and maintaining bones throughout life, but this has not been considered in recommended intakes.
Protein’s importance for bone health is further suggested by its ability to increase insulin-like growth factor (IGF-1; a growth hormone), calcium absorption and muscle mass.
A systematic review and meta-analysis, April 2017, found high compared to low protein intake was associated with 16% reduced incidence of hip fractures. They reported correlations between protein intake and bone mineral density, warranting further investigation. Also meriting research is whether increased protein can prevent or treat osteoporosis.
All in all, the review supports protein intakes above the RDA for preventing hip fractures and bone mineral density loss, concluding “This is the first systematic review of its kind that shows consuming protein above current recommended levels is beneficial for bone health.”
The review did not find any difference between plant and animal protein sources for preventing bone loss, but noted a dearth of data from which to draw definitive recommendations. However, protein quality matters.